An l-shell electron (binding energy = 26 kev) is removed from an atom that has an m-shell binding energy of 4 kev and an n-shell binding energy of 1 kev. if a free electron fills the vacancy in the l-shell, the characteristic x-ray produced will have an energy of

26 keV

Explanation:

The electron is being ejected from the L -shell which has a binding energy of 26 keV.

Now the electron is being added to fill the vacancy in the L shell. Since, the binding the energy of the electron for the L-shell is 26 keV, so the energy produced is also equal to this amount of energy.

So, the characteristic x-ray produced will have an energy of 26 keV.

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2